Gain Slope Issues in Microwave Modules

If you are a microwave hardware engineer you most likely have had a few sobering experiences when you test your new design the first time, particularly wideband high frequency modules – they almost never look like the model. Many of the bigger issues come down to physics. Broadband modules e.g. 2 to 18 GHz virtually always have gain roll-off at the high end of the band, from a combination of transistor and package parasitic L’s & C’s give rise to gain roll-off and VSWR mismatch losses, while interconnect transmission lines have increasing loss with frequency.